Under some conditions, /proc/<pid>/maps might return nothing. If we
try and unwind in this case, we'll crash. Check this case and fail
the unwind.
Add checks that no other functions try and use map_ without
checking for nullptr.
Add logging when an unwind fails so it's clear what happened.
Bug: 21162746
Change-Id: I56ce51dda0cfc9db20475a441f118108196aa07c
Also simplifies the Darwin implementation of gettid, because
apparently libbacktrace had a better way of doing it.
Change-Id: I9e14f9176b167405a5aaa5b8a0db0327c7126271
When doing a local unwind, do not include the frames that come
from either libunwind or libbacktrace.
Bug: 11518609
Change-Id: I0ec8d823aebbfa0903e61b16b7e5663f3fd65e78
The object hierarchy was confusing and convoluted. This removes
a lot of unnecessary code, and consolidates the BacktraceCurrent
and BacktraceThread code into BacktraceCurrent.
Change-Id: I01c8407d493712a48169df49dd3ff46db4a7c3ae
